Module composition 

Composition dispatcher — THE typed execution path for routed effects.

Wave-b V2 rebuilds composition dispatch as a typed, mandatory runtime seam. The deleted composition_dispatch.rs and recompute_mob_peer_overlay*.rs (wave-a tombstones ce2dbe35e / f5e366f38) were stringly-typed helpers that callers opted into. This module is their structural opposite:

• Typed end-to-end. Producer identity is ProducerInstance carrying typed CompositionId, MachineInstanceId, MachineId. Effects travel as EffectPayload<E> where E is the producer composition’s typed seam-effect sum (the ProducerEffect trait bound). Route resolution returns a typed RoutedInputDescriptor carrying MachineInstanceId / InputVariantId / Vec<(FieldId, FieldId)>. Signal-kind routes travel through the parallel SignalPayload<S> / CompositionSignalDispatcher surface and resolve to typed RoutedSignalDescriptor values.
• Mandatory, not optional. The trait has no fallback surface. Routed effects whose route is declared in the composition schema MUST resolve through the dispatcher; unresolved routes are a typed DispatchRefusal::UnresolvedRoute error, not a silent drop. Signal-kind routes live on a separate index inside RouteTable and MUST resolve through CompositionSignalDispatcher.
• Compile-time presence/absence. A MeerkatMachine either has a composition dispatcher attached (via the with_composition constructor) or it does not (the standalone / single-machine test path). The two cases are distinguished by a typed CompositionBinding discriminant, never by Option<Arc<dyn CompositionDispatcher>>.

The default catalog-backed dispatcher (CatalogCompositionDispatcher) consumes a RouteTable built from any meerkat_machine_schema::CompositionSchema and delivers each resolved RoutedInputDescriptor to a per-consumer-instance ConsumerSurface supplied at wire-up. The per-composition codegen module emitted by meerkat-machine-codegen (B-4 + B-4b) plugs in as the ProducerEffect implementation — route_to_input is equivalent to consulting the RouteTable built from the same schema.

Re-exports

pub use route_table::RouteTable;

pub use route_table::RouteTableError;

pub use route_table::RoutedInputDescriptor;

pub use route_table::RoutedSignalDescriptor;

Modules

route_table

Typed route index consumed by super::CatalogCompositionDispatcher.

Structs

CatalogCompositionDispatcher

Default catalog-backed dispatcher.

CatalogCompositionSignalDispatcher

Default catalog-backed signal dispatcher.

DispatchOutcome

Outcome when a routed effect is successfully dispatched.

ProducerInstance

Typed identity of the producing machine instance inside a composition.

RouteKey

Typed route key: (composition, route).

SignalDispatchOutcome

Outcome when a routed signal is successfully dispatched.

Enums

CompositionBinding

Typed binding attached to a runtime that holds a dispatcher.

DispatchRefusal

Reasons the dispatcher refuses a routed effect.

EffectPayload

Typed effect payload. Generic over the producer composition’s seam-effect sum (see the codegen-emitted {Composition}Effect enum).

FieldValue

Typed view over a producer-field value projected through a route binding.

OwnedFieldValue

Owned counterpart of FieldValue used when delivering a routed input across the consumer-surface boundary. Moving owned values means the consumer can construct its typed input without re-borrowing the producer.

SignalDispatchRefusal

Reasons the signal dispatcher refuses a routed signal.

SignalPayload

Typed signal-route payload. Generic over the producer composition’s seam-signal sum.

Traits

CompositionDispatcher

Composition dispatcher trait.

CompositionSignalDispatcher

Composition signal dispatcher trait.

ConsumerSurface

Delivery surface for one consumer instance inside a composition.

ContextProvider

Typed, owner-supplied context provider for an OwnerProvided binding.

ProducerEffect

Marker trait for the seam-effect sum emitted by meerkat-machine-codegen::render_composition_driver. Producer effect enums implement this to expose the typed variant id alongside their domain body — the dispatcher consults it without inspecting the enum.

ProducerSignal

Marker trait for the seam-signal source sum consumed by CompositionSignalDispatcher.

SignalConsumerSurface

Delivery surface for one signal-consuming instance inside a composition.